CORE C PROJECT SUMMARY Pannexin 1 (Panx1) forms plasma membrane ion channels that release important intercellular signalling molecules, specifically ATP and UTP, under pathological and physiological conditions; the channels also support uptake of various fluorescent dyes that have traditionally been used to mark apoptotic cells (e.g., YO-PRO-1, TO-PRO-3). In this PPG application, novel mouse models are employed to ascertain contributions of Panx1- mediated ATP/UTP release, (and other metabolite release, when needed) to various aspects of cardiometabolic diseases, and to understand corresponding mechanisms of Panx1 channel activation. Cell Physiology Core centralizes the functional analysis of Pannexin channels by absorbing, optimizing and standardizing the key assays of universal significance to all four projects. These include: (1) Analysis of Panx1 channel function in primary cells by electrophysiology and dye uptake assays and; (2) Electrophysiological characterization of novel small molecule modulators of Pannexin channels. Similarly, the core also takes the initiative in the development of innovative tools and methods that can provide a clear technical edge to the entire research program. This includes generation of novel Panx1 variants and gene-edited mouse lines, generated by CRISPR/Cas9 technology. In executing these centralized goals, often of salience to the entire research program, the core recognizes the paramount importance of data quality and reproducibility. For the vertical and horizontal integration proposed in this PPG, this core sits at the interface between cellular and systems levels of analysis of Panx1 function.